New York (CNN) -- Parents, beware of Tagged.com, says New York Attorney General Andrew Cuomo.

Cuomo threatened Thursday to sue the teen-targeted site for exposing children to graphic images of child pornography if it doesn't develop a plan to change the way they monitor and respond to complaints of inappropriate conduct.

"This is one of the worst social networking sites that we've encountered.," Cuomo said at a news conference in New York City.

Cuomo said he only wants the company to live up to its own standards as touted on its website -- including that they are dedicated to child safety and responsive to complaints.

Cuomo said a three-month undercover investigation by his office revealed significant lapses in Tagged's response to user reports of graphic images of child pornography, including photos of an adult performing oral sex on a girl who appears to be younger than ten years old.

In a statement sent to CNN, Tagged General Counsel Louis Willacy the company was working "closely and cooperatively" with Cuomo's office to come to a quick resolution "in the best interest of our members' safety."